Kurš apprecējās ar Grand Duchess Anna Petrovna of Russia?

Grand Duchess Anna Petrovna of Russia (Russian: А́нна Петро́вна; 27 January 1708 – 4 March 1728) was the eldest daughter of Emperor Peter I of Russia and his wife Empress Catherine I. Her younger sister, Empress Elizabeth, ruled between 1741 and 1762. While a potential heir in the reign of her nephew Peter II, she never acceded to the throne due to political reasons. However, her son Peter III became Emperor in 1762, succeeding Elizabeth. She was the Duchess Consort of Holstein-Gottorp by marriage. She was born in Moscow and died in Kiel in her youth, at the age of 20.

Charles Frederick, Duke of Schleswig-Holstein-Gottorp (German: Karl Friedrich, Herzog von Schleswig-Holstein-Gottorp) (30 April 1700 – 18 June 1739) was a Prince of Sweden and Duke of Schleswig-Holstein-Gottorp and an important member of European royalty. His dynasty, the Dukes of Schleswig-Holstein-Gottorp, were a cadet branch of the ancient House of Oldenburg, which at that time was ruling Denmark-Norway. His mother was a sister of Charles XII of Sweden. Charles Frederick married a daughter of Peter the Great and became the father of the future Peter III of Russia. As such, he is the progenitor of the Russian imperial house of Holstein-Gottorp-Romanov and the patrilineal ancestor of all Russian emperors starting with Peter III, except for Catherine II.